We propose to study the health service implications of recent demographic and epidemiologic trends in dementia among the elderly occurring in the United States. The proposed research will conduct analytic studies on longitudinal health status and health service use data from community demonstration projects funded from Section 2176 of the Omnibus Budget Reconciliation Act of 1981 (i.e., National Channeling Study, California Multipurpose Senior Services Project, and the Georgia Alternative Health Services Project) for the population with characteristics of dementia. Based on the results of these studies we will produce national estimates of the acute and long term care (LTC) service use patterns of the population with characteristics of dementia based on nationally representative survey data (i.e., National Long Term Care Surveys and National Nursing Home Surveys). By applying appropriate multivariate methodologies for multidimensional event history analyses, a number of specific analytic studies will be conducted to identify dementia profiles to represent the relations between multiple cognitive, functional, behavioral, and other health-related characteristics of cognitively impaired individuals in the elderly population. A model of health service use, where use will be estimated conditionally on the dementia profiles (in order to control for intensity and type of cognitive impairment), will be developed and used to forecast the current and future prevalence of cognitive impairment and dementia in the total U.S. elderly population and among specific population subgroups (e.g., by age and sex) and the type and amount of health care services consumed (and expected to be consumed) by the population with characteristics of dementia. An important feature of those projections is that the impact of dementia and cognitive impairment will be weighted by the scope and intensity of symptoms presented. This represents the reality that many processes producing dementia (e.g., Alzheimer's disease) have a lengthy natural history with a gradual evolution of symptoms and impairment. Prior studies have tended to either over or under estimate the impact of dementia because the intensity of the disease manifestation was not represented. We will be interested in examining how the increase in elderly population groups "leads" the growth in disease burden because of the 7 to 8-year average survival of persons with Alzheimer's disease (the predominant physiological process underlying dementia). Analytic studies will be conducted in order to accomplish four specific aims: 1) production of age-specific prevalence estimates and projections of cognitive impairment and dementia in the community and national study populations using standard epidemiologic methods and clinical criteria for defining a case for the purpose of providing descriptive epidemiologic statistics about the study populations and for making comparisons of the prevalence estimates and projections for the study populations with those of previously evaluated populations (Kokmen et al., 1989; Evans et al., 1989), 2) develop a conceptual and analytical scheme for identifying the dimensions of dementia most relevant to acute and long term care (LTC) service use and the development of profiles to best represent those dimensions, 3) identification of acute and LTC service use patterns of the population with dementia (specific to its severity and differences in its manifestation in various populations), and 4) development of a model of the acute and LTC service use of the population with characteristics of dementia.